In answer:
1.The point is that WNW are not releasing kits, like the Dr.I, BE.2c, Jenny, etc, that will sell in huge numbers. Why? "Traditional" model manufacturers make profits. They maximise profits. Why turn away from making profits and release something like the DFW & Pflaz D.XII, which are hardly in demand? They'll probably release them sometime - I'm not claiming any "rules" that stop them doing so - but why not release a Dr.I now? It'll sell like hot cakes.
2. "Traditional" manufacturers maximise profits. That's their raison d'etre. Having smaller production runs than demand warrants is just crazy - it's turning money away. The risk of having kits and no buyers is a risk of being in business, but selling out repeatedly is just not the way to run a business - not a "traditional" business.
3. "Tons of reasons", but with WNW kits selling out time after time, it's obvious that WNW are not making enough kits. "Costs, storage and efficiency" are outweighed by revenue. What other "traditional" kit manufacturers allow a significant percentage of their entire production catalogue to sell out time after time, in a relatively short time?
4. I'm not holding the "little demand" kits against WNW. I love them! But it's not what a "traditional manufacturer" would do. It fails to maximise revenue and profits.
5. WNW's marketing is minimal. Tamiya have their own magazine, they trail new kits months in advance. WNW's don't. They have taken magazine ads, but not very many & not regularly. They didn't even sell via wholesalers until relatively recently.
6. WNW's released not one, but three boxing's of the Felixstowe - with no warning whatsoever. They have "Christmas Surprises" regularly. They have recently trailed a few kits, but that's not the norm - you are obviously a little late to WNW.
7. Again, that's what "traditional" manufacturers do. They sell kits with the most demand. I love WNW kitting weird subjects. I prefer it. But why do they do it, it doesn't maximise revenue? Because Peter Jackson wanted that kit. That's not "traditional".
8. The secrecy runs , for many kits, until they are released. No pre-marketing. Why? It's not "traditional", other manufacturers market their releases months and months in advance.
9. You know it's a DR.I decal included in a kit boxing, stop being facetious.
10. The SE.5a was being kitted before Roden released theirs. Same with the DH.2. The Pfalz D.III of Roden is a different kit to the D.IIIa. The Fokker D.VII & E.III are truly awful Battle Axe kits that are avoided like the plague. Same with the Camel. Again, it's not a "rule" - my point is that "traditional" manufacturers kit the most in demand aeroplanes.
11. A single French aeroplane, and a fairly innocuous one at that, when demand for Neiuports and SPAD's has been ignored - again, not very "traditional". Why?
12. My entire point is you claim that WNW are a "traditional" manufacturing company. The points I've raised above illustrate why, in my opinion, they are not. It's nothing to do with "rules", or breaking rules - it's just that they don't operate like other manufacturers.

Why no Be.2, Dr.I, DH.4, Jenny, Nieuports, SPADS, early Albie's, Caudrons, Breguets, Farmans, Macchis, Avro 504k, Short seaplanes, 1 & 1/2 Strutter, Gunbus, etc, etc? Why allow popular kits to sell out? Why not make larger runs, or make further runs? Why kit planes with little demand? Why no marketing? Why just release kits with no warning? Why ignore subjects that would sell in large numbers? Why the secrecy? Why provide decals for competitors kits? Why the reluctance to make kits of already released subjects? Why the Anglo-German infatuation?
This doesn't seem to be a "traditional kit manufacturer", as I know of no other manufacturer that operates like WNW. Companies tend to want to maximise profits, & I'm pretty sure WNW are not doing that. Making money - probably - but not maximising profits.

Just breathtakingly beautiful.
2019 is only a few weeks old and I've already found the model of the year.
However did you manage to get the corrugated detail? It looks amazingly realistic - so well proportioned and spaced.

If WNW never make another model, I'll still have enough left to see out my days. Plus the Roden kits, plus Special Hobby are dabbling in WWI, plus Silver Wings inter-wars stuff, plus Copper State Models movement into 1/32, plus another company would fill the large 1/32 WWI void if WNW packed up, plus the moulds would be sold on, as they are too valuable not to.
So, I'm not worried at all.

The weathering is first rate - although "factory fresh" looking models have a place, they are only representative of a brand-new aeroplane.
Yours looks like an aeroplane that flew in Europe weather at 1,500 mph.

200? I'd guess the UK has far more than 200! Look at WNW, their 2 seaters are in excess of £100 and they sell out. And that's a relatively small niche. So I'd say closer to 20,000 than 200.
However, I tend to agree that 1/48 sells more. It's cheaper, takes up less space, has less parts and builds quicker. I can see the attraction, just as 1/24 sells less than 1/32.
So the 1/48 market is bigger, with more models of more types of aeroplanes. However, I'm not sure how that translates into the AM industry, as I'd guess a of the kits are bought by grannies and parents, and by part-time model builders, who may only model one kit a year, or one kit in their lifetimes. They are not going to be buying AM. Plus the existing 1/48 AM industry seems quite crowded. If you are nimble enough, you can sell quite high volumes of 1/32 AM as you have expert knowledge that many companies can't match. Maybe analyse your sales, see if you are making more money from 1/48 or 1/32?

As noted by others, this is a limited edition, initial production run with the clear fuselage. I'm sure the next run will be considerably bigger.
At this price, a kit like this will be aimed at hardcore modellers like us. I'm sure it could, however, sell 10,000 worldwide. North America, Europe and Japan alone represent almost 800,000,000 people. Add in China's huge, fast growing, relatively wealthy middle class and the potential market climbs over 2 billion. 10,000 equals 0.0005%. Or if you've bought a Tamiya 1/32 Spitfire, then you'd maybe consider buying a 1/32 Lancaster, and I think Tamiya sold a lot of Spitfires, demand enough to do 3 versions.

A lot more than 2000. I'd wager in the 5 figures, perhaps, based on nothing but a wild guess over worldwide demand.
"Corrections" means new moulds, means more huge expense. I'd be very surprised if that happens, especially with 1. The way the after-market operates, and 2. The very low price. I'll take a low priced imperfect model over a near perfect expensive model every time. We can sometimes get hung up over accuracy as the be all and end all, when in fact enjoyment is the aim. I'd also guess the additional models they'd sell if they "corrected" the kit would not get anywhere near the additional cost. For most people, the box art is as important as accuracy!

I've long assumed some listings are just plain money laundering or tax avoidance, such are the multiples asked.
Only ever contacted one buyer - he was selling 1/32 kit boxes. No kits, just the empty boxes.